biolocal:Linux raid

RAID Management

Verify raid status:

mdadm --detail /dev/md0

Examine disks:

mdadm -E /dev/sdd1

Stopping a raid disk:

mdadm -S /dev/md0

Assemble a already configured raid disk:

mdadm -A /dev/md0 /dev/sda1 /dev/sdb1 /dev/sdc1
mdadm -Af /dev/md0 /dev/sda1 /dev/sdb1 /dev/sdc1 (force)

RAID creation

Create new "Linux raid autodetect" partitions (type code fd in fdisk) on each disk:

fdisk /dev/sda

Create the array

mdadm --create /dev/md0 --level=5 --raid-devices=4 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1

Add the device list string into the file /etc/mdadm.conf:

DEVICE /dev/sda* /dev/sdb* /dev/sdc* /dev/sdd*

Automatically complete the configuration appending the raid device information:

mdadm --detail --scan >> /etc/mdadm.conf

Manage array disk replaces

Put the corrupted disk in failure status and remove it:

mdadm /dev/md4 -f /dev/sdd1
mdadm /dev/md4 -r /dev/sdd1

Prepare the new disk with a "Linux raid autodetect" partition and add it to the raid:

mdadm --add /dev/md0 /dev/sdd1